Radio frequency (RF) circuits, such as voltage controlled oscillators (“VCOs”), low noise amplifiers (“LNAs”), and phase locked loops (“PLLs”), are widely used in wireless communication systems. Various RF circuits that operate at high frequencies, for example, in gigahertz (GHz) frequency ranges, are integrated with other devices to form a system. In some instances, the RF circuit is applied to a microwave or millimeter-wave (mmW) apparatus, which usually refers to a device capable of transmitting signals at a frequency approximately 10 GHz to 300 GHz.
In some approaches, the frequency is achieved by thinning a gate dielectric or shallowing a source/drain region. In some embodiments, in order to obtain a lower resistance-capacitance (RC) time constant, a sheet resistance of the gate electrode is reduced. In some approaches, the device is formed to include asymmetric lightly-doped drain (LDD) regions.